Tell/Ask your DBA to partition your dev table since prod is partitioned. I dislike the fact that dev and prod are not mirrors in terms of setup. Unless of course you are testing a new aspect in dev ...

Well, based upon your described symptoms, you slow down over time. You did not indicate that there were a lot of concurrently running jobs running at the time. That implies that your CPU should not ...

Adding more CPU is nuts and the IBM guy who is recommending that is a newb. Not to mention you've just signed up for 50% more licensing cost because of a product shortcoming. This is not LOAD based ...